Hey guys! Im working for a little project and I have a problem.
I use:
Arduino Uno
ESP8266
Generic pushbutton
MQTT broker
I can't send data("1" or "0") with my pushbutton to the MQTT broker.
My wifi connection is fine and I can publish messages to the broker but I can't use the ESP8266 to send data with the pushbutton.
Pushbutton connection: see attachment jpg
ESP8266 connection:
GND -------------------------- GND
GP2 -------------------------- Not connected (open)
GP0 -------------------------- GND
RXD -------------------------- RX
TXD -------------------------- TX
CHPD ------------------------ VCC
RST -------------------------- Not connected (open)
VCC -------------------------- 3.3V
Arduino uno's reset is connected to ground.
My code:
#include <ESP8266WiFi.h>
#include <PubSubClient.h>
// Update these with values suitable for your network.
const char* ssid = "wifissid";
const char* password = "wificode";
const char* mqtt_server = "mqttipadres"; // IP address of the Broker
uint8_t my_str[6]; // sting to store the incoming data from the publisher
String str;
int buttonPushCounter = 0; // counter for the number of button presses
int buttonState = 0; // current state of the button
int lastButtonState = 0; // previous state of the button
const int buttonPin = 4; // the pin that the pushbutton is attached to
const int ledPin = 12;
WiFiClient espClient;
PubSubClient client(espClient);
long lastMsg = 0;
char msg[50];
int value = 0;
void setup_wifi() {
delay(10);
// We start by connecting to a WiFi network
Serial.println();
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
randomSeed(micros());
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
}
void callback(char* topic, byte* payload, unsigned int length) {
Serial.print("Message arrived [");
Serial.print(topic);
Serial.print("] ");
for (int i = 0; i < length; i++) {
char receivedChar = (char)payload[i];
Serial.print(receivedChar);
if (receivedChar == '0')
digitalWrite(ledPin, HIGH);
if (receivedChar == '1')
digitalWrite(ledPin, LOW);
}
Serial.println();
}
void reconnect() {
// Loop until we're reconnected
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
// Create a random client ID
String clientId = "ESP8266Client-";
clientId += String(random(0xffff), HEX);
// Attempt to connect
if (client.connect(clientId.c_str())) {
Serial.println("connected");
// Once connected, publish an announcement...
client.publish("outTopic", "hello world");
// ... and resubscribe
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
// Wait 5 seconds before retrying
delay(5000);
}
}
}
void setup() {
Serial.begin(115200);
// initialize the button pin as a input:
pinMode(buttonPin, INPUT);
// initialize the LED as an output:
pinMode(ledPin, OUTPUT);
setup_wifi();
client.setServer(mqtt_server, 1883);
client.setCallback(callback);
}
void loop() {
// read the pushbutton input pin:
buttonState = digitalRead(buttonPin);
if (buttonState == HIGH) {
digitalWrite(ledPin, HIGH);
client.publish("outTopic", "1"); //
// if the current state is HIGH then the button
// went from off to on:
} else {
digitalWrite(ledPin, LOW);
// if the current state is LOW then the button
// went from on to off:
client.publish("outTopic", "0"); //
}
// Delay a little bit to avoid bouncing
delay(50);
// save the current state as the last state,
//for next time through the loop
lastButtonState = buttonState;
{
if (!client.connected()) {
reconnect();
}
client.loop();
}
}
void clearstring() {
//Serial.flush(); // clears the buffer, you dont need this
for (int r=0; r<7; r++){
my_str[r] = '\0'; // deletes each block
}
// my_str[0] = '\0';
// my_str[1] = '\0';
// my_str[2] = '\0';
// my_str[3] = '\0';
// my_str[4] = '\0';
// my_str[5] = '\0';
// my_str[6] = '\0';
}
Thank you 
